Becoming a 401(k) millionaire represents a significant milestone in retirement planning. According to recent data, the average age at which individuals attain this status is 59 years old, typically after 26 years of consistent contributions to their retirement plans. The length of time typically required to become a 401(k) millionaire underscores the importance of long-term saving and disciplined investment strategies.

Working with a financial advisor can help you develop a retirement strategy that aligns with your specific needs and objectives.

The Rise of 401(k) Millionaires

The number of 401(k)-created millionaires hit a record high in 2024, surging by 27% year-over-year to reach 537,000 individuals, according to Fidelity Investments. This notable increase follows a strong market rebound from prior years of volatility. After weathering inflation spikes and interest rate uncertainty, retirement accounts gained ground as equities stabilized and bonds delivered better yields.

While the term “401(k) millionaire” might suggest a rare financial achievement, the data shows that with time, strategy and consistency, many retirement savers could reach this milestone.

Average Age and Tenure

The typical 401(k) millionaire is 59 years old and has been contributing to the same retirement plan for approximately 26 years. This longevity offers a clear lesson: Time in the market matters more than timing the market. Most individuals who’ve reached this level of savings didn’t do it overnight. They built wealth steadily over decades, allowing compound returns to do the heavy lifting.

This also highlights the value of job stability and maintaining long-term participation in a retirement plan. Frequent job changes or cashing out a 401(k) early can dramatically hinder long-term growth. Instead, those who roll over accounts and stay invested benefit from uninterrupted compounding.

Generational Breakdown

Generation X now makes up the majority of 401(k) millionaires, accounting for 57% of the total. Baby Boomers follow at 41%, and Millennials — who are earlier in their careers — make up just 2%. 

This generational breakdown aligns with life stage realities: Gen Xers and Boomers have had decades to build up their savings, while Millennials are just beginning to see the power of compounding interest take effect.

However, Millennials are expected to grow their wealth quickly over the next decade. As they earn more, receive employer matches and see market gains, many could become millionaires—especially those who start early and contribute often.

Saving Habits

What sets 401(k) millionaires apart from the average retirement saver is their savings rate. On average, these individuals contribute over 17% of their pre-tax income to their 401(k) plans, including employer contributions. For many, this means contributing the annual IRS maximum or close to it for multiple years.

Let’s consider a hypothetical example: An individual earning $90,000 annually who contributes 10% of their salary and receives a 5% employer match will save $13,500 per year. If they maintain that level of savings for 30 years with an average return of 7%, they could end up with over $1 million in their 401(k). Those who increase their contributions over time, or begin saving earlier, stand to accumulate even more.

Automatic escalation features, where contribution rates gradually increase over time, also contribute to growing balances. Additionally, many 401(k) millionaires rebalance their portfolios regularly, stay invested during downturns and avoid early withdrawals. All these practices protect long-term growth.